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Class _X^l4i_ 
Book_ l£_&_ 



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10 



COPYRIGHT DEPOSIT. 



DEFECTS 

OF 

VISION AND HEARING 

IN THE 

PUBLIC SCHOOLS 



A Hand ^Book for tl?e 
Use of Teachers 



J. WHITEFIELD SMITH, B.S., M.D., 

Bloomington , ///. 

LECTURER ON PHYSIOLOGY AND HYGIENE, ILLINOIS \VES- 

LEYAN UNIVERSITY; OPHTHALMIC AND AURAL SURGEON 

TO THE BROKAW HOSPITAL; OCULIST AND AUR1ST 

TO THE CHICAGO & ALTON RAILWAY CO. 



O J --' ^ ' 

11 



A. FLANAGAN COMPANY 
CHICAGO NEW YORK 



LIBRARY of CONGRESS 
Two Cepies Received 

MAR II 1904 

^ Copyright £atry 
CLASS oj XXo.No, 
COPY 6 



\P ^ 



COPYRIGHT, 1904 

BY 

A. FLANAGAN COMPANY 



• • • *• 



.♦ .* . »-» 



TYPOGRAPHY BY 

MARSH, AITKEN & CURTIS COMPANY 

CHICAGO 



TO 

MY WIFE 

WHO FORMERLY WAS A TEACHER IN THE 

PUBLIC SCHOOLS 

AND WHOSE KINDLY SUGGESTIONS 

HAVE BEEN OF 

GREAT VALUE IN THE PREPARATION OF 

THESE PAGES 

THIS BOOK IS 

AFFECTIONATELY DEDICATED 



CONTENTS OF PART I 

CHAPTER I 

Defects of Vision Depending upon the Shape of 

the Eye page 

Far-Sightedness (Hypermetropia) — Inspection by the 
Teacher — The Pupil's Experience — Method of 
Determining Far-sightedness 13 

CHAPTER II 
The Influence of Far-Sightedness on School Work 

Retards Intellectual Progress— Renders Some Parts 
of the Curriculum Impracticable — Requires the 
Best Facilities for School Work — Produces Reflex 
Nervous Symptoms 20 

CHAPTER III 

Near-Sightedness (Myopia) 

Is Exactly the Opposite of Far-Sightedness — Inspec- 
tion by the Teacher — The Experience of the 
Pupil — Method of Determining Near-Sightedness. 28 

CHAPTER IV 

Near-Sightedness Caused by School Work 

Near-Sightedness Is Acquired — It Requires Proper 

Methods of Study — Modifies the Course of Study 

— Restricts Employment — Demands Special Care 

in the Student . . . .• 32 

5 



6 Contents 

chapter v 

Astigmatism page 

Definition — Inspection by the Teacher— The Pupil's 
Experience in Astigmatism — The Determination 
of Astigmatism 4° 

CHAPTER VI 
The Most Common of All Refractive Errors 
Astigmatism of the Normal Eye — Interferes with 
Literary Pursuits — Affects the Discipline of the 
School 46 

CHAPTER VII 

Cross- Eyes (Strabismus) 

Definition — Inspection by the Teacher — The Pupil's 
Experience — The Determination of the Squinting 
Eye 50 

CHAPTER VIII 
Disadvantages of Cross-Eyes 

Cross-Eyes the Result of Far-Sightedness and Near- 
sightedness — Produces Weak Sight from Non- 
Use — Reduces Visual Power — Embarrassing to 
Students 53 

CHAPTER IX 

Weak Sight (Asthenopia) 
Scope of the Term — Inspection by the Teacher — The 
Pupil's Experience — The Correction of Weak 
Sight 58 



Contents 7 

chapter x 

Weak Sight in Relation to Education PA ge 
Not Common in the Grade Schools — Demands Time 
in Educational Work — Weak Sight in Nervous 
Students — In Educational Departments — In the 
Study of Science — In Art 61 

CHAPTER XI 

Color-Blindness 

The Color-Sense — Objective Symptoms — Subjective 
Symptoms — The Detection of Color-Blindness . ... 67 

CHAPTER XII 

Color-Blindness in the Public Schools 

Color-Blindness in Sex — Color-Blindness and the 
Kindergarten — Color-Blindness in the High School 
and College — Dangerous in Some Employments — 
Incurable 73 



CONTENTS OF PART II 

CHAPTER I 

Deafness 

The Sense of Hearing — Objective Symptoms of 
Deafness — Subjective Symptoms — Determination 
of the Hearing Powers 81 



8 Contents 

CHAPTER II 

Deafness in the Student PAG e 

Deafness in Infancy — Effect of Deafness on the 
Scholar — Its Effect on the School — Deafness 
Affects the Student's Work — Deafness in Special 
Education 88 

CHAPTER III 

Deaf-Mutism 

Its Cause — Objective Symptoms — Subjective Symp 
toms — Examination of Deaf Mutes 95 

CHAPTER IV 
Education of Deaf Mutes 
The Oral System— The Sign System— The Semi- 
Deaf 101 



PREFACE 

The preface of this book is not the 
author's apology for its publication. 
There is among educators in the public 
schools a confessed need of proper in- 
struction respecting the vision and hear- 
ing of the children under their care; and 
since state boards of health and school 
authorities generally throughout the 
United States are earnestly considering 
this matter, and practical tests are now 
being required of teachers, to ascertain 
if defects of vision or hearing exist among 
their pupils, this need is all the more 
urgent. 

Experience teaches and statistics show 
that many children in the public schools 
are, in the pursuit of their education, 
laboring under the disadvantages of de- 
fective vision and hearing. Where such 
defects have been brought to notice, they 
have in most cases been remedied. 

9 



io Preface 

In the preparation of these pages effort 
has been made to avoid technicalities, and 
where scientific terms have been .used 
they have in the same connection been 
explained. 

The thought has been to call attention 
to the more common defects of vision and 
hearing which are so frequently observed 
in the public schools; and to set forth the 
methods by which the teacher can detect 
them by direct inspection and by suitable 
tests, at the same time having a compre- 
hensive understanding of the nature of 
the trouble. 

It is hoped that the book may prove 
helpful to the teacher and at the same 
time be of benefit to the pupil who may 
be so unfortunate as to have defective 
vision or hearing. Fully realizing its 
many shortcomings, the author offers it 
for the friendly consideration of the 
teachers of our public schools. 

J. Whitefield Smith. 

Bloomington, Illinois, 
October 12, 1903. 



PART I 



Defects of Vision and Hearing 
in the Public Schools 



CHAPTER I 

defects of vision depending upon the 
shape of the eye 

Far - Sightedness (Hypermetropic). — 
One of the most common defects of vision 
depending upon the shape of the eye is 
far-sightedness. This condition is caused 
by the globe of the eye being too short 
from the front backward. Rays of light 
passing through the eye are not properly 
focused on the retina. In far-sightedness, 
if parallel rays of light were to be brought 
to a common focus, they would have 
to be projected to a point behind the 
retina. 

Far-sightedness is often noticed in sev- 
eral members of the same family, thus 
showing its hereditary tendency. As to 

13 



14 Defects of Vision and Hearing 

the cause of far-sightedness, the defect is 
usually conceded to be due to arrested 
development. 

Inspection by the Teacher. — The 
form and appearance of the eye will give 
valuable information in regard to the 
defect of vision in far-sightedness. In- 
spection will reveal the apparent or actual 
smallness of the eye; as well as the deep 
position of the eye within the orbit, which 
is also significant. If we separate the 
eyelids at their outer angle and direct the 
far-sighted pupil to look in the opposite 
direction, thus bringing the external side 
of the eye prominently into view, it will 
be observed that the lateral portion is 
strongly curved, or very convex, and the 
eye will appear somewhat flattened from 
the front backward. The orbits are shal- 
low, and the general contour and expres- 
sion of the face also are characterized by 
a flat appearance. 

These features are most marked in the 
highest grades of far-sightedness. 

The Pupils Experience. — The far- 
sighted pupil experiences the most difn- 



Defects of Vision and Hearing 15 

culty when he attempts to use his eyes at 
near work. In the reading of small type, 
letters on the page become indistinct, and 
it is with effort that he maintains a distinct 
image of the print. He is momentarily 
relieved by looking away from the reading 
matter for a few seconds and allowing 
the vision to brighten; but on resumption 
of work the vision soon becomes indis- 
tinct. The pupil frequently must stop 
reading and rub the eyes gently, or hold 
them firmly for an instant, in order to get 
relief. The eyes pain and fill with tears, 
and the power to focus them on the print 
becomes exhausted. Not infrequently 
the pupil must discontinue his work alto- 
gether. 

The far-sighted pupil often changes the 
position of the book, trying to bring it 
into a brighter or stronger light, so that 
the pupils of the eyes may contract and 
thereby cut off some of the rays of light, 
and thus aid the vision. Young far- 
sighted pupils often hold the book very 
close to their eyes and squint up the lids 
until the margins almost touch, in order 



1 6 Defects of Vision and Hearing 

to cut off the divergent rays of light. 
The skin of the eyelids is wrinkled into 
folds, and the brows are drawn down; the 
pupil peers at the print, and while he is 
reading, his expression is anxious and 
troubled, betraying his imperfect vision. 

If the far-sightedness is very pro- 
nounced, the eyes look tired and sleepy 
after protracted reading. Artificial illu- 
mination or insufficient light increases the 
difficulty, and the eyes usually suffer more 
on dark days or in the evening. The 
strain on them causes them to ache, and 
pupils complain of headache which affects 
chiefly the forehead, but may extend all 
over the head. Dizziness is frequently a 
symptom of far-sightedness. ' 

If the conditions continue unfavorable, 
a train of symptoms supervene which are 
very noticeable. The lids look swollen 
and heavy, their margins are reddened, 
and a sensation of weight and heat is ex- 
perienced by the sufferer. The conjunc- 
tiva,* both of the lids and of the eyeball, is 

* Conjunctiva: The mucous membrane lining the 
eyelids and covering the anterior part of the eyeball. 



Defects of Vision and Hearing 17 

congested, and the lids feel dry and 
rough. These disturbances may also 
lead to congestion of the inner structure 
of the eye. 

Method of Determining Far-Sight- 
edness. — An approximate estimate of 
far-sightedness may be made by the use 
of the test type, and the one usually 
employed for the examination is Snel- 
len's. 

The card containing the printed letters 
should be placed on the wall, in a good 
light, at a distance of twenty feet from 
the pupil. The series of lines on the card 
are graduated in size, and are numbered 
so that the pupil should read correctly, 
with each eye separately, the line of type 
corresponding to the number indicating 
the distance at which it should be legible. 
If he cannot do this, we suspect an error 
of vision due to the shape of the eye or 
disease of the organ. 

If the pupil can read only the line of 
type marked No. 30, we infer that he has 
about two-thirds vision as compared with 
a person having normal sight. In making 



1 8 Defects of Vision and Hearing 

this estimate, we take for the numerator 
of the fraction indicating the pupil's 
acuteness of vision, the distance across 
the room from the pupil to the test card 
(twenty feet); for the denominator of the 
fraction we take the number of the line 
of type that he can read correctly at the 
given distance. 

It must be remembered that this is only 
an approximate test of the acuteness of 
the pupil's vision; but the test, if carefully 
made, will enable the teacher to determine 
whether or not any considerable amount 
of error exists. Pupils with slight degrees 
of far-sightedness may be able to read 
the normal line on the test card; in this 
case they are able to overcome the error 
by an effort in seeing. 

The above test is employed to deter- 
mine approximately the pupil's acuteness 
of vision, or, in other words, the power of 
distant vision. It is also necessary to test 
the near vision. This is done by ascer- 
taining the nearest point that the finest 
type (Snellen's, marked 0.50D) can be read 
correctly with each eye separately; the 



Defects of Vision and Hearing 19 

small type should be read as close as four 
and one-half inches from the eye; and 
read easily at six or seven inches, if the 
pupil is under twenty-one years of age. 



CHAPTER II 

THE INFLUENCE OF FAR-SIGHTEDNESS ON 
SCHOOL WORK 

Retards Intellectual Progress. — So 
far we have endeavored to give the reader 
some idea of far-sightedness, its causes, 
and a list of symptoms some of which 
appear in every case. From the fore- 
going it is obvious that a child with keen 
intellectual faculties, if he is so unfortu- 
nate as to have a high degree of far- 
sightedness which is allowed to go 
uncorrected, should not be expected to 
do his school work comfortably nor to 
attain the proficiency in his studies that 
otherwise might be looked for by his par- 
ents and teachers. The child's ability to 
study is restricted. His opportunities are 
necessarily limited, and what he does 
accomplish is with pain and inconven- 
ience. 

The child does not realize his condi- 

20 



Defects of Vision and Hearing 21 

tion, for he cannot discriminate between 
good vision and vision that is defective. 
Because of the condition of his sight, he 
has never known what it means to see 
easily and well. How important it is, 
then, for parents to know the condition 
of their children's eyes! And it certainly 
is very desirable for teachers to know 
that their pupils are not laboring under 
the disadvantage of defective vision. 

Every teacher understands that the 
proper use of the eyes, although to some 
extent an unconscious process, is an im- 
portant factor in education. Indeed, the 
training of the eyes to observe carefully 
and discriminate accurately is, in itself, 
an educational process. About ninety 
per cent of our sense-perception comes to 
us through sight, and if in a child this 
function is impaired, his ability to become 
acquainted with the external world is like- 
wise impaired. 

In the education of children the pre- 
sentative powers or the perceptive facul- 
ties are, properly, the first to receive 
attention, and in their training the vision 



22 Defects of Vision and Hearing 

is appealed to many times more than any 
of the other senses; hence the necessity 
for the child to acquire habits of careful 
visual perception. Let us illustrate the 
use of the eyes in an example of an object 
lesson, and it will be seen how necessary 
it is for children to have perfect vision; 
and if any should have an error, how im- 
portant it is that it should be corrected. 

If we take a beautiful and instructive 
picture and place it before a class of chil- 
dren, some will observe it to a better ad- 
vantage than others, because they can see 
it better. The outlines, form and linea- 
ments are more closely observed; the 
mental image and the impression on' the 
mind are better and more lasting. When 
the pupils come to study it in detail, the 
several parts are more clearly discerned by 
those who have good visual powers. In 
the study of a picture, children should not 
be allowed to pass hurriedly from one 
portion to another, but each feature 
should be accurately observed and fixed 
in the mind until all of the salient points 
have been examined. 



Defects of Vision and Hearing 23 

If the child has seen the several parts 
of the picture clearly, it is not difficult 
for him to recall them separately or col- 
lectively as he chooses. But, on the con- 
trary, if the picture has simply been 
looked at rather than seen, and the suc- 
cessive parts have come dimly into view, 
and the whole has appeared as through a 
fog or mist, the child's mental picture will 
be indistinct and imperfect, and his 
knowledge of the picture will be corre- 
spondingly deficient. Thus the condition 
of far-sightedness retards intellectual at- 
tainment. 

Renders Some Parts of the Curric- 
ulum Impracticable. — In our deductions 
on far-sightedness we are considering 
only the disadvantages due to bad vision. 
There are many other conditions of the 
eyes that may interfere in acquiring an 
education, but for the present our atten- 
tion is directed to a state of vision due to 
a physical defect of the organ. As we 
have already observed, in far-sightedness 
the formation and shape of the eye are 
imperfect, and as a consequence its func- 



24 Defects of Vision and Hearing 

tion, and everything depending on the 
proper performance of this function, are 
modified. 

Perhaps there is no better way to illus- 
trate these facts than by the use of con- 
crete examples. 

Let us take the elementary course in 
art instruction — a department in the pub- 
lic schools that is of so much importance — 
and note some of the hindrances that the 
far-sighted pupil experiences. In nature 
study take the foliage, the different kinds 
and forms of leaves, and ask the far- 
sighted pupil to make an original sketch 
or copy. He will experience little diffi- 
culty in drawing the gross forms, or the 
different shaped leaves, such as the linear, 
lance-shaped, oval, ovate, heart-shaped, 
kidney-shaped, etc., but when it comes to 
the venation, where he is required to rep- 
resent the veins, veinlets and nerves with 
precision, the task becomes an arduous, 
and in some instances an impossible, one. 

The same general conditions are true in 
many other departments of the school 
course. In music we find that the far- 



Defects of Vision and Hearing 25 

sighted pupil has trouble in seeing the 
form, shape and position of the notes and 
characters on the staff; these constantly 
blur and become indistinct. In mathe- 
matics it is with great difficulty that he 
distinguishes the exponents, literal coeffi- 
cients and algebraic signs; and in higher 
mathematics his vision is severely taxed 
in drawing the geometrical figures illus- 
trating the various theorems. Map-draw- 
ing is laborious, and in the study of the 
languages abundant proof is found of his 
extreme visual burden. 

Requires the Best Facilities for 
School Work. — One of the most impor- 
tant considerations for far-sighted stu- 
dents is the question of light. Nothing is 
more fatiguing to the eyes than to read 
or write or draw by an insufficient light. 
Every far-sighted pupil should if possible 
be seated so that the rays of light will fall 
over his left shoulder upon his work, while 
his eyes are in shadow; the quantity of 
light should be abundant and the quality 
of sufficient brightness. Next in impor- 
tance, perhaps, is the kind of print he 



26 Defects of Vision and Hearing 

must read; the school books should be 
printed in good, clear type, not too closely 
compressed, nor smaller than small pica. 

Children should sit comfortably erect, 
avoiding a bending or stooping posture, 
so that the return of blood from the head 
and eyes is not retarded. They should 
hold the book directly in front of the eyes, 
at a distance of twelve or fourteen inches. 

Far-sighted pupils should not read con- 
tinuously for long periods of time, as they 
may completely exhaust their power to 
focus the print. It is better to work for 
shorter periods with intervals of relaxa- 
tion. 

While these remarks apply especially 
to children who are far-sighted and who 
have not had their defect of vision correct- 
ed by suitable glasses, we must not lose 
sight of the general principle that school 
children should not be overburdened with 
near work — that is, work at close range 
which overtaxes the eyes. 

The' education of far-sighted children 
should have in view the choice of a pro- 
fession or an occupation in which their 



Defects of Vision and Hearing 27 

vision is not required for very fine or con- 
tinued work. 

Produces Reflex Nervous Symptoms. — 
From the list of symptoms already con- 
sidered it is apparent that the general 
nervous system must at least sympathize 
with the organ of vision under so tremen- 
dous a strain. Brain activity is inter- 
rupted by far-sightedness, and no amount 
of will power can fix the attention of the 
pupil on his books. But this is not the 
most detrimental feature; nervous symp- 
toms, reflex in character — such as sick 
headache, neuralgia, chorea, etc.— may 
be directly attributed to far-sightedness 
or to some other visual defect. Not only 
is the child's school work rendered diffi- 
cult, but his health may become seriously 
impaired. In these conditions depending 
on error of vision, medication is worse 
than useless. The only relief that can be 
permanent is in properly correcting the 
condition by suitable glasses. 



CHAPTER III 

NEAR-SIGHTEDNESS (MYOPIA) 

Is Exactly the Opposite of Far- 
sightedness. — By near-sightedness we 
mean a condition in which the diameter 
of the globe of the eye from the front 
backward is so long that parallel rays, in- 
stead of being focused on the retina, are 
brought to a common focus in front of 
the retina. 

Far-sightedness exists from birth, near- 
sightedness is acquired. Far-sightedness 
is better adapted for distant vision, near- 
sightedness for near vision. Far-sighted- 
ness is the rule in the uncivilized races; 
near-sightedness may be regarded as the 
result of civilization. Far-sightedness is 
found among the uneducated classes; 
near-sightedness occurs among the edu- 
cated, occasioned by the constant demand 
on near vision. Far-sightedness is suited 
to outdoor occupations, near-sightedness 
to indoor work. 

23 



Defects of Vision and Hearing 29 

Near-sightedness is most frequently 
caused by the optic axis being too long; 
that is, the diameter from the front back- 
ward is longer than in the normal eye. 

Inspection by the Teacher. — The con- 
dition of near-sightedness may be fairly 
well determined by direct inspection. In 
the higher degrees of near-sightedness 
the eyeballs are large and appear prom- 
inent. The palpebral fissure* is wide; 
and the equatorial surface is not so 
strongly curved, but on the contrary is 
elongated and extends backward nearly 
straight. In high grades of near-sighted- 
ness the pupil of the eye is dilated, and 
the person has to some extent an expres- 
sionless countenance because he cannot 
determine distinctly the features of those 
at a little distance from him. 

Another symptom characteristic of 
near-sightedness is the manner in which 
pupils move the head in reading. They 
hold the book still, but close to the face, 
and move the head from the beginning to 

* Palpebral fissure: The opening between the eye- 
lids. 



30 Defects of Vision and Hearing 

the end of the line they are reading. 
Frequently in near-sightedness one eye 
will diverge, or be directed outward. 

The Experience of the Pupil. — Near- 
sighted pupils have a habit of blinking the 
eyes, to which fact is due the term myopia. 
The subject squints up the lids to shut out 
the light, and thus diminish the circles of 
diffusion on the retina. Distant objects 
are seen indistinctly, and the near-sighted 
person's horizon is limited and appears as 
in a mist or fog. He, however, sees well 
and with little or no effort objects near at 
hand. In these particulars the condition 
is just the opposite of far-sightedness. In 
that form of error, we saw that the sub- 
ject could see distant objects more clearly 
and easily than those near by. 

The near-sighted pupil experiences pain 
in the eyes, and a sense of fatigue and 
dread of light. The lids are irritable and 
the eyeballs are sensitive to pressure. 
The conjunctiva is congested, and the 
subject frequently complains of seeing 
black spots floating before the eyes; 
headache also is a very common symptom. 



Defects of Vision and Hearing 31 

Method of Determining Near-Sight- 
edness. — The remedy for near-sighted- 
ness is found in properly fitting concave 
glasses. In estimating the condition and 
amount of error in near-sightedness, we 
may proceed as in the directions given for 
determining far-sightedness. 

Snellen's test type for distance should 
be placed on the wall on a level with the 
pupil's eyes, in a good illumination, at a 
distance of twenty feet, and the line noted 
at which the pupil can read all of the let- 
ters plainly and correctly. If he cannot 
read the line marked No. 20, he has a 
defect. In testing the near vision we may 
find that the pupil can read the small let- 
ters of Snellen's 0.50D very well at four 
and one-half or five inches from his eyes, 
but cannot read the distant type dis- 
tinctly. In this case suspect near-sighted- 
ness. 



CHAPTER IV 

NEAR-SIGHTEDNESS CAUSED BY SCHOOL 
WORK 

Near-Sightedness Is Acquired. — This 
defect practically never occurs in the new- 
born child; and since it develops later in 
life, and, in a large majority of instances, 
in connection with eye-strain in children 
whose vision has been unduly taxed at 
near work, it is regarded as a disease. 

It is not so prevalent among children 
who have not been sent to school at an 
early age. Near-sightedness occasioned 
by excessive study in school has been 
rightly named "School Myopia." Near- 
sightedness is not so common in the 
grades as in the high school; when chil- 
dren have finished the work in the re- 
spective grades and come to the duties of 
the high school, a correspondingly greater 
amount of work is required, and the dan- 
ger of near-sightedness is increased. And, 

32 



Defects of Vision and Hearing 33 

following this, in the demands of a uni- 
versity education the danger is still 
greater. 

Near-sighted pupils — especially those 
who have many degrees of error — should 
be cautioned in regard to the excessive 
use of their eyes at near work. Internal 
changes of the eye are liable to be induced, 
and the vision may become defective to 
an alarming extent. 

Requires Proper Methods of Study. 
— Of first importance in the case of near- 
sightedness is an attempt to stop the 
development and progress. This is 
mainly accomplished by avoiding the con- 
tinual straining of the eyes at near work. 
If near-sightedness is developed in very 
young children, their games and sports 
should receive attention and be under 
competent supervision. Children with 
high grades of near-sightedness do not 
care for outdoor sports; they do not see 
well, and for this reason prefer indoor 
amusements. They readily become inter- 
ested in puzzles, dissected maps, authors, 
card-sewing, etc. But this may prove 



34 Defects of Vision and Healing 

burdensome to their eyes, and increase 
their defective vision. 

In their school work they should be 
given books printed in good clear type of 
sufficient size. The writing should be 
of good-sized letters and with uniform, 
fairly heavy lines. Very fine work in the 
industrial departments — such as fine sew- 
ing, delicate drawings, etc. — should be 
avoided altogether by near-sighted chil- 
dren. 

The book should be held in front of 
the near-sighted pupil, at an angle of 
forty-five degrees to the plane of the face. 
The importance of good illumination 
cannot be too strongly emphasized. 
Nothing is more productive of near-sight- 
edness than attempts to do near work by 
insufficient light. This not only favors 
the development of the defect, but in- 
creases it when it is once established. 
Children should never be compelled to 
read or study by a dim light, and in case 
of near-sightedness they should do as 
little near work as possible by artificial 
light. 



Defects of Vision and Hearing 35 

Modifies the Course of Study. — We 
have seen that in far-sightedness some 
departments of the curriculum are influ- 
enced by the condition of bad vision, and 
in the error we are now considering the 
same thing is true. In our illustration of 
the study of a picture or painting, far- 
sighted pupils worked at a disadvantage. 
In the case of near-sightedness, let us sub- 
stitute the original landscape of which the 
picture or painting was a copy, and 
observe the effect. If the distant view 
consists of a farm scene with herds of cat- 
tle and horses, ripened fields of grain, 
clumps of trees, babbling brooks and 
silent ponds, bevies of birds, luxuriant 
vegetation, beautiful flowers and foliage, 
etc., the near-sighted pupil can see only 
the gross forms, and the objects appear 
hazy and indistinct; all small objects are 
obscured from view, and if he should be 
asked to enumerate what he had seen, 
the landscape could not be recognized by 
the description. 

In the schoolroom near-sighted pupils 
have great difficulty in reading the work 



36 Defects of Vision and Hearing 

placed on the blackboard, if they are 
seated at some distance from it. The 
same difficulty is experienced if they are 
required to draw a map or make a draw- 
ing from a copy hung on the wall. In 
order to see a map placed on the wall 
they must go close up to it. 

In most of our schools a great deal of 
work consisting of reviews, original prob- 
lems in arithmetic, maps to be copied, 
spelling lessons, examination questions, 
etc., are placed on the board by the 
teacher for the pupils to copy. It is in 
this sort of work that the near-sighted 
pupil has the most difficult task. 

It is the very popular and commendable 
custom of some teachers to take their 
pupils on excursions to the country to 
study nature and natural scenery; geo- 
logical and botanical specimens are gath- 
ered and classified, and in this way the 
flora and fauna of the locality are made 
familiar to the student. Near-sighted 
pupils cannot engage in this mode of 
study to the same extent as pupils with 
normal vision. They are even less 



Defects of Vision and Hearing 37 

capable of it than those who are far- 
sighted. 

Restricts Employment. — The fact that 
near-sighted eyes usually have sharp vis- 
ion for objects near by leads their pos- 
sessor to think that he has very strong 
eyes. This is by no means necessarily 
true. The reason near-sighted people 
have good vision at close range is that 
the image of the object on the retina is 
larger than in the case of the normal eye, 
or of the far-sighted eye; and again, the 
near-sighted person's far point* is much 
nearer to his eye, and he requires but 
little effort to see distant objects. 

For these reasons near-sighted pupils, 
when allowed a choice, naturally select 
occupations requiring close application of 
the eyes on fine work at close range. 
This frequently proves to be a fatal mis- 
take, for, as we have seen, it tends to in- 
crease the amount of error. It is the duty 
of physicians and teachers to discourage 

* Far point {punctum re?notum): the farthest point 
of distinct vision, or the farthest point at which an object 
can be distinctly seen with the eye in repose. 



38 Defects of Vision and Hearing 

near-sighted pupils from engaging in occu- 
pations of this kind. 

There is a long list of employments that 
near-sighted people should avoid: they 
should never be, for instance, jewelers, 
watchmakers, engravers, lithographers, 
typesetters, or proofreaders; and for 
stenography and shorthand, needlework 
and embroidery, they are totally unsuited. 

Demands Special Care in the Stu- 
dent. — In this age of books we are apt to 
forget, in our eagerness for intellectual 
attainment, that children differ as much 
in regard to the strength of their eyes and 
ability to use them as they differ in their 
physical strength and constitution. What, 
then, is a reasonable task for one child 
may prove a burden to another. Chil- 
dren with near-sighted eyes should be 
considered as possessing weak visual 
organs, and though such eyes may be use- 
ful, and with proper care render efficient 
service, they are subjected to many dan- 
gers in the acquirement of an education. 

If the near-sightedness is ''progressive" 
in character, the need for care is all the 



Defects of Vision and Hearing 30, 

more imperative. No amount of educa- 
tion can compensate for the loss of vision. 
Statistics bearing on this point have 
caused much anxiety, and endeavors have 
been made to put a stop to the evil. 
Careful direction and counsel from com- 
petent medical authority only should 
determine the near-sighted pupil's career 
in school, and the teacher can be of valu- 
able service in pointing out to parents the 
extreme necessity of timely action in the 
care of their children's eyes. 



CHAPTER V 



ASTIGMATISM 



Definition. — By astigmatism we mean 
a condition of the eye depending upon 
irregular curvatures of the cornea or 
an oblique position of the crystalline lens, 
which, instead of bringing parallel rays of 
light to a common focus, produce a diffu- 
sion image on the retina. 

Most frequently the cornea is the seat 
of astigmatism, and in such cases the state 
of the vision differs in the meridians of the 
eye; whereas, in irregular astigmatism, 
the same meridian presents different de- 
grees of curvature. In regular astigma- 
tism there are always two principal me- 
ridians — one of the greatest and one of 
the least refractive power — and these are 
always at right angles to each other. The 
vertical meridian usually has the highest 
refraction. 

It should be remembered that the 

cornea is not perfectly spherical in the 

40 



Defects of Vision and Hearing \\ 

normal eye; it is a little wider in the 
transverse diameter (about i mm). There- 
fore, the longest radius of curvature is in 
the horizontal meridian, and this is usu- 
ally the meridian of the least refractive 

power. 

We found that in far-sightedness and 
in near-sightedness the bad vision is due 
to the shape of the eyeball, taken as a 
whole. In astigmatism we find that the 
error is due to peculiarities of shape, but 
in this case it pertains to the shape of the 
cornea or lens only, and more especially to 
the shape of the cornea. If all the merid- 
ians of the cornea were alike in focal 
length and curvature, there could be no 
corneal astigmatism; but when they differ 
in curvature, the meridian of the shortest 
radius will have the highest refraction, 
and the meridian of the longest radius 
the lowest refraction. 

From this it is evident that no well- 
defined image can be focused on the 
retina; there is always an overlapping of 
different parts of the object, which pro- 
duces a blurred or diffusion image. 



42 Defects of Vision and Hearing 

Inspection by the Teacher. — The 
symptoms of astigmatism are in many 
respects similar to those of far-sighted- 
ness and of near-sightedness; for in many 
cases astigmatism is associated with each 
of these errors. One of the most com- 
mon symptoms that may be observed is 
the inability of the subject to see well 
either near by or far away, if the degree 
is high. The eyes are weak and sensi- 
tive to light; the conjunctiva is reddened; 
the margins of the lids are irritated, and 
frequently small tumors are found upon 
the lids. 

In looking with one eye at an object, 
the pupil usually turns his head slightly 
to one side instead of looking squarely 
at it. In very high grades of astigma- 
tism, by direct inspection we may observe 
the oval appearance of the cornea. 

Another symptom of importance is the 
distorted appearance of the image cast on 
the cornea by any object reflected upon it — 
particularly by a circular or a square object. 

The Pupil's Experience in Astigma- 
tism. — The symptoms of astigmatism are 



Defects oj Vision and Hearing 43 

characteristic; perhaps the most common 
symptom, aside from bad vision, is head- 
ache. It is estimated that at least sixty 
per cent of headaches not depending on 
disease are caused by astigmatism — alone 
or in connection with other visual errors. 
Even low grades of astigmatism are very 
productive of headache, which may be 
situated in the forehead and temples or 
may extend all over the head. 

Many of the symptoms already enu~ 
merated in connection with far-sighted- 
ness and near-sightedness belong also to 
astigmatism, viz., pain, redness of the con- 
junctiva, squinting of the lids, dread of 
light, and irritability not only of the eyes 
but of the nervous system, induced by the 
frequent attacks of headache. 

The manner of seeing objects is a 
means of determining astigmatism in the 
pupil, for to the astigmatic eye lines 
running in certain directions will appear 
distinct, while the same kind of lines ex- 
tending at right angles to these will ap- 
pear to be blurred. In other words, a 
straight line may look distinct or indis- 



44 Defects of Vision and Hearing 

tinct to an astigmatic eye, according to 
the direction it takes. In high degrees of 
astigmatism all circular surfaces appear 
elliptical. The full moon, for example, 
appears to have a long axis; a circle 
placed on the blackboard will look like a 
ring drawn out; and some of the figures 
on the clock dial will appear clear, while 
others of the same size and brightness are 
hazy and indistinct. 

Let us notice how letters look to an 
astigmatic eye. We will presume that 
the meridian at fault is either the vertical 
or the horizontal. Some letters, like H, 
are made principally with vertical strokes, 
while others, like E, contain more hori- 
zontal lines. If the astigmatic eye sees E 
more plainly than H, because the hori- 
zontal lines of E appear more distinct, we 
conclude that the vertical meridian is 
normal, as the horizontal lines of the let- 
ter E are composed of an infinite number 
of short vertical lines, and the vertical 
stroke of E is composed of short hori- 
zontal lines. 

In reading small print the same thing 



Defects of Vision and Hearing 45 

holds true, in so far as some letters or 
parts of letters appear more distinct than 
others. This confusion of the retinal 
image keeps up a constant demand on the 
vision for a better focus, and thus the eyes 
are under a continual strain, which leads 
to pain in the eyes and severe headache. 
The Determination of Astigmatism. — 
This defect may be fairly well determined 
by the use of Snellen's Astigmatic Chart. 
The pupil should be seated twenty feet 
from the chart and asked to select, with 
each eye separately, the blackest or most 
distinct lines. If he selects the horizontal 
line, the horizontal meridian of the eye is 
at fault. If the vertical line appears the 
most distinct, the vertical meridian of the 
eye is in error. If all the lines of the 
chart appear equally distinct, astigmatism 
is not indicated. 



CHAPTER VI 

THE MOST COMMON OF ALL REFRACTIVE 

ERRORS 

Astigmatism of the Normal Eye. — In 
1793 Thomas Young, who was himself 
astigmatic, discovered this form of error, 
and brought it to notice. Because of the 
shape of the normal eye, there is ordi- 
narily a difference of refraction of the 
two principal meridians, which gives rise 
to a small amount of astigmatism. If this 
in no way interferes with the vision, it is 
called normal astigmatism, or regular 
astigmatism of the normal eye. 

In order to understand why this is true, 
it must be remembered that the cornea is 
not a segment of a sphere, but of an 
ellipsoid, with its widest diameter in the 
horizontal direction. The average diam- 
eter of the vertical meridian is about 1 1 
mm. and of the horizontal meridian about 
12 mm. Hence, there would be a little 

discrepancy in the normal eye. When 

46 



Defects of Vision and Hearing 47 

greater differences in the curvature of 
the two principal meridians exist, there 
are also disturbances of the acuteness of 
vision, and calls for correction by the use 
of cylindrical glasses. 

Interferes with Literary Pursuits. — 
In the earlier years of childhood, when 
the school work is not burdensome or 
fatiguing to the eyes, and when there is 
more freedom in the intervals of relaxa- 
tion from study, children do not complain 
so much from the effects of astigma- 
tism. But as the work grows harder, and 
more consecutive hours are required at 
study, astigmatic eyes become painful and 
weary. The ambition of the pupil is re- 
strained and his zeal diminished. 

If the pupil is attentive and studious in 
school, it is only because of the kindly 
solicitation or admonition of the teacher — 
"Please give attention to your books," or, 
"Let there be no idle ones in the room." 

With this defect of vision, as with the 
others we have considered, some kinds of 
school work are more trying than others. 
Music, as might be expected, will be 



48 Defects of Vision and Hearing 

somewhat difficult, for it has to do with 
lines and spaces, notes and characters 
extending in different directions. Writ- 
ing and drawing are very fatiguing to 
astigmatic eyes, and painting becomes not 
only burdensome but painful. 

Affects the Discipline of the School. 
— The teacher realizes that, in order to 
attain the best order in school, it is neces- 
sary to keep the pupils busy and inter- 
ested. This is impossible with children 
suffering from defective vision, and partic- 
ularly when the refractional error pro- 
duces a general condition of irritability. 
If a child is nervous, or affected, with pain 
or discomfort of the head or eyes, he 
naturally becomes indifferent to his work, 
and to the discipline necessary to main- 
tain good order. The condition of astig- 
matism is liable to beget habits of care- 
lessness and absent-mindedness in school 
children; it is not that these shortcomings 
are traits of their character, but their 
painful vision prevents them from being 
attentive and from concentrating their 
minds on their work. 



Defects of Vision and Hearing 49 

The restlessness that is observed in 
some pupils is no doubt due in many 
instances to the reflex nervous state 
induced by astigmatism. Frequently chil- 
dren will manifest a tendency to look out 
of the window — at no object in particular, 
but simply as a means of relief from the 
strain upon their eyes. These symptoms 
should be carefully distinguished from 
idleness on the part of the pupil. 

The importance of ascertaining the 
condition of astigmatism, whether it exists 
by itself or in connection with other 
errors of vision, cannot be too strongly 
emphasized; for the comfort and health 
of the child may depend largely on the 
state of the eyes. It is understood to- 
day that nearly every function of the 
body may be influenced or modified by 
visual defects depending on refractional 
errors. 



(T 



HAPTER VII 



CROSS-EYES (STRABISMUS) 

Definition. — Cross-eyes may be de- 
fined as a condition in which one of the 
eyes deviates from the normal direction, 
when the subject attempts to look at an 
object with both eyes. This condition is 
also called "squint." 

Inspection by the Teacher. — Squint 
is usually evident in the appearance of 
the eyes. The condition is commonly 
known as cross-eyes, and ordinarily direct 
inspection will determine whether or not 
in looking at a distant object both eyes 
are directed alike to it. 

If one eye turns inward toward the 
nose and the other is directed straight 
forward toward the object, the former is 
denominated the "squinting eye," and the 
latter the "fixing eye." 

The Pupil's Experience. — The most 
common symptom, perhaps, is that of 

50 



Defects of Vision and Hearing 51 

double vision (diplopia). If the muscular 
equilibrium is disturbed to the extent of 
producing double vision, the condition be- 
comes very annoying; every object ap- 
pears as two, and the pupil is in a state 
of constant confusion for a time, but fre- 
quently the double vision ceases, for the 
pupil soon learns to suppress or exclude 
the false image of the squinting eye. 

Another symptom is that the vision of 
the squinting eye is not so good as that 
of the fixing eye. 

If the squint is due to paralysis of the 
nerves that supply the ocular muscles, 
there are the following symptoms: 
Characteristic carriage of the head; 
vertigo or dizziness, resulting from the 
difficulty in distinguishing between the 
true and the false image; a loss or limita- 
tion of movement of the squinting eye. 

The Determination of the Squinting 
Eye. — Hold an object, say a lead pencil, 
vertical before the eyes, about two feet 
from them, and gradually bring it to the 
face, observing the eyes all the time. If 
one of the eyes "fixes" the pencil, and, as 



52 Defects of Vision and Hearing 

the pencil approaches the face, the other 
turns in, the eye turning in has conver- 
gent strabismus. If, while the pencil 
approaches the face, one eye turns out- 
ward, the case is one of divergent strabis- 
mus. If both eyes follow the pencil for a 
little distance, and then one stops or 
makes a few jerking movements, that 
eye has paralytic strabismus. 



CHAPTER VIII 

disadvantages of cross-eyes 

Cross-Eyes the Result of Far-Sight- 
edness and Near-Sightedness. — It is esti- 
mated that seventy-five per cent of all 
cases of convergent strabismus are asso- 
ciated with far-sightedness. In conver- 
gent strabismus the eye is directed inward, 
and there are several factors that enter 
into the causation. The power of the 
eyes to focus is usually taxed in far-sight- 
edness, in order to maintain a distant 
image, and this probably is one important 
agent. Again, where squint occurs, one 
eye is usually defective in vision and 
may have been so some time before 
the squinting appeared as a result; hence 
unequal vision of the two eyes is no 
doubt an important factor. Since cross- 
eyes develops at an early age of child- 
hood, when the child begins to use his 
focusing power to fix near objects, it 
would seem that "close work" is inti- 

53 



54 Defects of Vision and Hearing 

mately associated with this muscular 
error. 

Divergent squint is the rule in near- 
sighted eyes; the eye turns out toward 
the temple. About sixty per cent of all 
subjects of divergent squint are near- 
sighted. The condition is not developed 
in early childhood, but makes its appear- 
ance in youth and early adolescence. 
The tendency of divergent squint is to 
become worse as the subject grows 
older. 

Produces Weak Sight from Non-Use. — 
Weak sight or blunt sight is developed in 
squinting eyes that have not been exer- 
cised or trained in seeing. In children, if 
the squinting is alternating in character — 
that is, if first one eye fixes an object and 
then the other — the strength of vision in 
each eye may remain about the same, but 
if the individual always uses the same eye 
to "fix," the squinting eye usually grows 
decidedly dim. 

It seems to lose its vision from non- 
use; the sensitiveness of the retina to 
light and to images is reduced, and its 



Defects of Vision and Hearing 55 

normal functional activity cannot be re- 
stored. This applies to the retina before 
it has developed its full strength and 
capacity. From this it is evident that 
children affected by squint should have 
early medical advice, and the cause of the 
trouble be determined and removed, if 
possible, at once. 

The treatment of cross-eyes not due to 
paralysis but depending on refractional 
errors, should consist of the putting on of 
properly fitting glasses. Usually in chil- 
dren the squint will disappear in a few 
months; if it does not, surgical interference 
is suggested. 

Reduces Visual Power. — With cross- 
eyes, unless it is of the alternating 
variety, the child does his school work 
practically with one eye. Of course this 
is a disadvantage to a student, for many 
times the light in the room is such that it 
cannot be regulated or adjusted to suit 
the demands of the case. The light may 
come into the room from the side near 
the squinting eye, and thus place the 
work in shadow. Or, in cases of conver- 



56 Defects of Vision and Hearing 

gent strabismus, if the light should come 
from the side near the "fixing" eye, it 
would be diffused directly into the "squint- 
ing" eye. 

The same difficulties are encountered 
in divergent strabismus; only the condi- 
tions are the reverse. The student is 
compelled to seek a position that will give 
him the best light, whether it is comfort- 
able or not. 

A squinting eye that has become dim 
from non-use never becomes totally blind, 
but retains enough vision to become a 
very disturbing element in the act of see- 
ing. The visual burden is borne by the 
"fixing" eye, and if it has an error, the 
complication is all the more distressing. 

Embarrassingto Students. — Calisthenic 
drills and physical culture exercises con- 
stitute a prominent department in school 
work. These are begun in the primary 
grades and continued, to a certain extent, 
throughout the school course. Children 
with cross-eyes are placed at some disad- 
vantage in carrying out this part of the 
program. As their vision depends on one 



Defects of Vision and Hearing 57 

eye, many of their movements are awk- 
ward. 

The advantages of binocular vision — 
that is single vision with the two eyes — 
are numerous. Children must learn as a 
matter of education to measure with their 
eyes the objects of the field of vision in 
perspective, such as length, breadth and 
depth, size, space, motion, etc. 

These advantages enter largely into the 
various drills and exercises, which are a 
physical benefit as well as a mental 
training. Children whose vision is lim- 
ited to one eye by squint are unable to 
make as exact estimates in the perform- 
ance of these exercises as those who have 
perfect control of both eyes. 



CHAPTER IX 

WEAK SIGHT (ASTHENOPIA) 

Scope of the Term. — Weak sight in- 
cludes a group of symptoms that may 
appear in connection with far-sighted- 
ness, near-sightedness, or astigmatism; or 
it may exist quite independent of any of 
these errors. 

Inspection by the Teacher. — Regard- 
ing the appearance of the eyes in weak 
sight, the following may be observed: 
The eyes are red, due to congestion of 
the conjunctiva; they look weak, which is 
signified by their "weak sight"; the mar- 
gins of the lids are congested; there is 
dread of light, shown by the subject shad- 
ing the eyes, or directing them down 
toward the feet. The eyelids are fre- 
quently closed tightly so as to compress 
the eyeballs, or further relief is sought in 
pressing them tightly in their sockets with 

the fingers. 

58 



Defects of Vision and Hearing 59 

The Pupil's Experience. — The symp- 
toms are numerous and varied; pain, and 
the inability to use the eyes at near work 
with comfort, are, however, the most 
prominent. The pain may be situated in 
the eyes or may radiate through the head, 
occasionally extending to the back of the 
neck. Usually it is not severe in charac- 
ter, but is very persistent, being worse in 
the evening, after the day's work. 

The subject frequently complains of 
dizziness and a dazzling light before the 
eyes. The eyes are hot as well as pain- 
ful, and the discomfort is increased when 
they are further heated by the illumina- 
tion used in reading by artificial light. 

In extreme cases of weak sight, wake- 
fulness, palpitation of the heart, indiges- 
tion and nausea have been observed. 

The Correction of Weak Sight. — 
Weak sight associated with refractional 
errors, such as far-sightedness, near- 
sightedness, or astigmatism is usually 
relieved by proper glasses. 

In weak sight due to nervous condi- 
tions, absolute rest of the eyes should be 



60 Defects of Vision and Hearing 

enjoined and the nervous system treated 
by the use of tonics, alteratives, etc. The 
use of electricity is frequently very bene- 
ficial. 



CHAPTER X 

weak sight in relation to education 

Not Common in the Grade Schools. — 
Weak sight is not common in the grade 
schools. The children that are strong 
and healthy, even though they have some 
error of vision, may be able to overcome 
it by a vigorous effort, and the symptoms 
may not develop, or, rather, may be resist- 
ed for a few years. If their health be- 
comes impaired, or if their vitality is 
reduced from any cause, symptoms of 
weak sight will appear. 

Very marked cases of weak sight do 
appear in children, and the symptoms are 
aggravated by their work in the primary 
and intermediate grades; but as a general 
thing the distressing symptoms of weak 
sight are not developed until the pupil 
enters the high school or college. The 
extra burden thrown upon the eyes by 
the necessity of a great amount of read^ 
ing — not only of text-books, but of books 

61 



62 Defects of Vision and Hearing 

used in supplementary work on collateral 
subjects — is usually sufficient to produce 
the symptoms if an error of vision exists, 
or if the pupil is of a nervous tempera- 
ment. 

Demands Time in Educational Work. 
— Students affected with weak sight often 
make the mistake of attempting to do too 
much work. They should realize that 
the nervous condition induced by their 
state of vision disqualifies them to a cer- 
tain extent for long and protracted 
periods of study. Their health is in- 
volved in a measure with their education, 
and they should consider the importance 
of doing justice to both. 

To accomplish this the student with 
weak sight should give due regard to all 
hygienic requirements, and limit his 
school work to the time at his disposal. 
He should not attempt to hurry through 
the course, by taking an extra number of 
studies, nor to make up for work that he 
has not already accomplished, in order to 
enter grades with "advanced standing." 
His defect of vision necessarily demands 



Defects of Vision and Hearing 63 

time in acquiring an education, and his 
education, his health and the state of his 
vision will be better in the end if he will 
take, the reasonable time that his condi- 
tion requires. 

Weak Sight in Nervous Students. — 
Weak sight is most distinctly manifest in 
the inability to use the eyes at near work 
for any length of time. A student with 
weak sight can see fine print for a few 
minutes only, and then the vision blurs, 
the print is indistinct and the words seem 
to mingle; if he discontinues the work 
and begins again in the course of an hour 
or so, after five or ten minutes' use of the 
eyes the same thing occurs. This of it- 
self has a tendency to discourage nervous 
students and make them irritable. 

In connection with this, pain is inaug- 
urated in the eyes, and distressing head- 
aches supervene which quite unfit the stu- 
dent for work. A pre-existing nervous 
state may be the cause of the weak sight, 
or a condition of nervous prostration may 
be the result of weak sight. Children of 
nervous temperament and delicate consti- 



64 Defects of Vision and Hearing 

tution suffering from this condition of vis- 
ion should be warned in time, or the 
consequences may be serious. 

In Educational Departments. — The 
term education is so broad in its applica- 
tion that it is often necessary to speak of 
its various departments or special fields of 
activity. 

Individuals possessing weak sight can- 
not pursue certain lines of study or pro- 
fessional work to advantage. In type- 
writing, for illustration, the operator must 
first direct his eyes to the copy and then 
to the manuscript; this occasions an in- 
cessant change of the focus of the eye. 
Weak eyes soon become fatigued by this 
work. 

Another illustration of the disadvan- 
tages of weak sight is found in book- 
keeping; weak eyes become very tired in 
making the transfer from the day book 
to the ledger. 

Indeed, all kinds of study or employ- 
ment requiring the eyes to hold either an 
interrupted focus or a continued focus 
for any considerable length of time, must 



Defects of Vision and Hearing 65 

result in pain and discomfort to those 
possessing weak vision. 

In the Study of Science. — Mathe- 
matics and astronomy are very trying 
studies to students of weak sight. Mathe- 
matics being an exact science, each step 
in its process must be clearly seen by the 
eyes as well as with the mind. In the 
practical study of astronomy the eyes are 
exercised in accurate, instant observations 
as well as in mathematical computations. 
Physics and chemistry call forth a large 
amount of painstaking labor, both in the 
study of the text and in the practical ex- 
periments. Students possessing weak 
sight often find their eyes becoming very 
painful in performing some of the delicate 
tests and experiments. 

Zoology and botany present some diffi- 
culties. The histological work is very 
hard on weak sight, and the preparation 
and preservation of tiny specimens, to- 
gether with the study of their minute 
structure, are attended by fatigue and a 
feeling of discomfort in the eyes. 

In Art. — In the useful arts — such as 



66 Defects of Vision and Hearing 

agriculture, horticulture and some depart- 
ments of mechanical engineering — the 
pupil can perform the duties with a 
reasonable degree of comfort, compared 
with the demands on the vision in the 
application of the fine arts. 

An enormous strain is put upon the 
eyes in the execution of the fine arts — as 
in architecture, sculpture, drawing and 
decorating, painting, engraving, etc. 
These require the closest scrutiny with 
the eyes, and in individuals of weak sight 
these kinds of employment cannot be per- 
formed without much distress. 

Students so affected should be apprised 
of their condition early, if possible, and 
their education should be directed not 
only in the interest of their vision, but 
with some regard to their future work. 



CHAPTER XI 



COLOR-BLINDNESS 



The Color Sense. — In the preceding 
chapters we have been considering mainly 
the subdivision of the sense of sight 
known as the form-sense, and the method 
of determining it by means of the test 
letters. 

Another sense of sight that we need 
only mention is the light-sense, which is 
the power the retina possesses of distin- 
guishing variations in the intensity of 
light. 

Still another important subdivision of 
the sense of sight is the color-sense. This 
is the power which the retina possesses of 
perceiving color. 

Some individuals are unable to distin- 
guish colors, or, in other words, the color- 
sense is entirely absent, and all objects 
appear gray, with different degrees of 

intensity. This is known as total color- 

67 



68 Defects of Vision and Hearing 

blindness — a condition, however, that is 
very uncommon. 

Partial color-blindness is of more fre- 
quent occurrence, and is usually con- 
genital; it is regarded as hereditary. 
Color-blindness may be acquired as the 
result of disease or injury. 

Professor Dalton — a distinguished Eng- 
lish chemist who was affected with color- 
blindness, being red-blind — was the first 
to describe defects of the color-sense. 
He published, in 1774, an account of his 
own defect, which was of unusual interest 
to scientists. Because of the discoverer, 
color-blindness was given the name of 
Daltonism. 

Objective Symptoms. — Dr. J. Ellis Jen- 
nings, in his admirable work on color- 
blindness and color-vision, has enumer- 
ated, under the topical head, "Peculiar 
Look of the Color-Blind," a list of objec- 
tive symptoms which are very important 
and suggestive. They are expressed in 
the author's own words as follows: 

A peculiar look of the color-blind was first 
noticed by Professor Wilson, of Edinburgh, 



Defects of Vision and Hearing 69 

and described by him as "an absent, anxious 
glance," as "a startled, restless look," and as 
"an eager, prying, aimless air." Dr. B. Joy 
Jeffries has observed this peculiar look in a 
number of color-blind. He describes it as "a 
certain liquid look, as if the eyes were slightly 
suffused. ... It gives the color-blind person 
the appearance of not listening or not being 
interested in what is said to him." Professor 
Wartmann remarks, "I have observed, in the 
case of 'Daltonians' whose eyes are brown, 
a golden lustre of a peculiar tint, when the 
eye is viewed under an incidence of some 
obliquity." 

Subjective Symptoms. — Color-blindness 
is usually partial, and Helmholtz has 
classified it thus: blue-blindness, or violet- 
blindness, green-blindness and red-blind- 
ness. These embrace the three funda- 
mental colors, and where partial color- 
blindness exists, the subject loses the 
power to perceive one, but retains the 
power to distinguish the other two. 
Ordinarily, there are no subjective symp- 
toms giving rise to much annoyance 
except in certain business pursuits. The 
subject learns the names of colors, and 



70 Defects of Vision and Hearing 

learns to associate them with the object 
as a psychical rather than a visual act. 
He knows the old familiar similes, "blue 
as the sky," "green as grass," and "red as 
blood"; hence, in speaking of the sky, of 
the grass or of blood he would assign to 
each its proper color. 

The Detection of Color-Blindness. — 
There are several practical methods for 
testing the color-vision. That of Profes- 
sor Holmgren is convenient, and consists 
in determining the ability of the patient 
to match the various colors of skeins of 
yarn. The test skeins comprise (a) light, 
pure green, (b) rose-purple, (c) red. 

A number of skeins for the subject to 
select from are colored red, blue, yellow, 
green, orange, pink, purple, yellow-green, 
blue-green, violet, brown, and gray. 
These are of several shades and tints. 

The subject is seated at a table in a 
good illumination (daylight), and the 
skeins are placed in a bunch on a white 
cloth on the table; the subject should be 
informed that no two shades are exactly 
alike, but that he is required to select 



Defects of Vision and Hearing 71 

skeins from the bunch that resemble the 
test-skein in color; that he cannot find 
exact duplicates of the test-skein, and 
furthermore that his inability to name all 
of the various shades and tints of the 
colors correctly is no proof of his being 
color-blind. 

First Test: With this understanding, 
the subject may begin by selecting from 
the bunch, and laying near the green test 
skein, all the skeins of the same color. If 
his color-sense is normal, he will promptly 
select the green-tinted skeins and those 
only. If he is color-blind, either com- 
pletely or incompletely, he will select con- 
fusion colors, such as grays, pinks, stone, 
slate, yellows, drabs, fawn, etc. 

Second Test: The next test consists in 
determining the nature and degree of the 
color-blindness. 

The skeins are all mixed again, and this 
time a rose or rose-purple is used for the 
test. The subject is asked to continue as 
before in matching the test skein. If he 
confuses the colors, selecting either the 
purple, blue or violet, and these of the 



J 2 Defects of Vision and Hearing 

deeper colors, he should be considered as 
completely red-blind. If he attempts to 
match the rose skein with green or gray 
skeins, he is completely green-blind. 

Third Test: If the subject be asked to' 
match the red test skein according to the 
method above, if he is red-blind he will 
confuse green and dark shades of brown 
in his selection; if he is green-blind, he 
will select light shades of green and 
brown. 

Fourth Test: Blue-blindness or violet- 
blindness is indicated when there is a 
tendency to confuse purple, red and 
orange in matching the rose skein. 



CHAPTER XII 

COLOR-BLINDNESS IN THE PUBLIC SCHOOLS 

Color-Blindness in Sex. — It is esti- 
mated that four per cent of males and 
about one-fourth of one per cent of fe- 
males are color-blind. The proportion 
is one to twenty-five among males, and 
one to four hundred among females. The 
reason of color-blindnes being so rare 
among females is problematical; it is gen- 
erally supposed that the nature of their 
work in handling color develops their 
color-sense to a higher degree of per- 
fection, and according to the laws of in- 
heritance produces a sexual distinction. 

The red-blind are called protanopes, 
and the green-blind deuteranopes. Red- 
blindness is the most common form of 
color-blindness. 

Colored vision — the result of disease or 
of some irritation of the visual centers — 
may affect either sex alike. 

73 



74 Dejects of Vision and Hearing 

Red vision (erythropsia) sometimes oc- 
curs after an operation for cataract: all 
objects appear red— usually like a rosy 
dawn or a crimson sunset. Blue vision 
(kyanopsia) is occasionally met with in 
nervous children. Work Dodd has col- 
lected thirteen published cases of green 
vision, in which everything appears green 
to the individual. 

Thus we may be blind to the sensation 
of any one of the three fundamental 
colors — that is, blind to red, or green or 
blue (violet); or the vision maybe satu- 
rated with any one of the fundamental 
colors, in which case everything looks red 
or green or blue. 

Color-Blindness and the Kindergar- 
ten. — In considering the effect of color- 
blindness in the schools, we might, per- 
haps, better begin with the most rudimen- 
tary department, viz., the kindergar- 
ten. 

Kindergarten schools, unless they are 
very liberal in their requirements, may 
prove to be decidedly injurious to the 
vision of young children. The children 



Defects of Vision and Hearing 75 

enrolled in the day-nurseries and the 
kindergartens are usually from four to six 
years old, and the eyes at this age are 
delicate in structure; the ocular tissues 
are not well developed, and are not suited 
to visual labor at close range. However, 
the kindergarten has a field of usefulness, 
and under proper direction can start the 
little minds on their educational career 
to advantage. 

The instruction requiring the use of the 
eyes should be from large charts, maps, 
pictures and diagrams hung in good illu- 
mination on the wall. Near work should 
be persisted in only for a few minutes at 
a time. Since colored objects are so 
much used in this grade of work, both to 
amuse and instruct the children, it is 
obvious that if any are color-blind they 
cannot work without becoming confused 
and making the most awkward mistakes. 
They cannot learn to harmonize the 
colors in mat-weaving, daisy chains, card- 
sewing, etc. If the teacher will test her 
pupils' color-sense, she may find out why 
some make slow progress. 



76 Defects of Vision and Hearing' 

Color-Blindness in the High School, 
and College. — Color-blindness interferes 
with some branches of study prescribed 
in the school course. For example, in 
physics the chapter on optics, and par- 
ticularly that part treating of the decom- 
position of light, cannot be demonstrated 
to the color-blind. Those who are red- 
blind see only two colors of the rainbow 
viz., yellow and blue; hence the rainbow 
to the color-blind is theoretical and hypo- 
thetical rather than real. 

The study of chemistry furnishes an- 
other example of the disadvantages ex- 
perienced by the color-blind. In metallic 
chemistry many of the tests depend upon 
the color of the precipitates thrown down 
by the reaction of the solution with the 
reagents. Color-blind students of course 
have trouble in distinguishing the colors. 

In college work the use of the micro- 
scope presents some difficulties. In the 
preparation of the specimens the staining 
process is apt to be confusing, and in the 
laboratory work much depends on the 
proper application of the colors. 



Defects of Vision and Hearing 77 

Dangerous in Some Employments. — 
All employments in which color signals 
are used — such as the colored lights or 
flags used in railroad and marine serv- 
ice — are dangerous for the color-blind. 
Not only are their own lives in jeopardy, 
when they are thus employed, but the lives 
of those employed with them, and of the 
traveling public as well. 

Postoffice officials, government clerks, 
railroad employees, merchant marine and 
the United States army and naval service 
are now required to take an examination 
in color-vision. An education looking 
forward to employment in any of these 
public services should be preceded by a 
careful chromatic test, for many times 
young men in school who have an ambi- 
tion for this kind of work, later may be 
disappointed to find out that they have 
defective color-sense. 

In the authors experience recently, in 
the examination of 247 adult males for 
railroad service, 15 were color-blind. 
Some of these were already in the rail- 
road employ, and had been for years, but 



y8 Defects of Vision and Hearing 

when their defect was discovered they 
were no longer regarded as satisfactory 
for the service. 

Incurable. — Color-blindness cannot be 
cured. It is no doubt due to paralysis, or 
to the absence in the retina of the per- 
ceptive organs for color. 

No amount of study or work with colors 
will improve the color-sense where it is 
defective or absent. The normal color- 
sense may be, improved by judicious edu- 
cation, and the most delicate tints and 
shades of color discriminated, but in the 
color-blind no improvement is to be ex- 
pected. Disturbances of the color-sense 
due to disease or accident may disappear, 
but congenital color-blindness is perma- 
nent. 

Color-blindness does not necessarily 
interfere with the vision, and eyes defect- 
ive in color-sense may be normal in every 
other respect. 



PART IT 



CHAPTER I 

DEAFNESS 

The Sense of Hearing. — We have seen 
in the preceding chapters how important 
is the manner in which luminous vibra- 
tions, or the rays of light, are brought to 
a focus on the retina. In our considera- 
tion of hearing we shall see the like im- 
portance of having the aerial vibrations 
or sound waves brought to the labyrinth. 

We saw that if the cornea is not sym- 
metrical, and interferes with the proper 
focusing on the retina of the rays of light, 
the vision is impaired. Likewise, if the 
membrana iympani, or the middle ear, is 
defective and interferes with the im- 
pingement of the sound waves upon the 
labyrinth, the hearing is disturbed. 

Functionally, the ear may be regarded 
as consisting of two portions; the con- 
necting apparatus and the perceptive ap- 
paratus. The former consists of the ex- 
ternal ear, comprising the auricle and 



82 Defects of Vision and Hearing 

meatus, and the middle ear or tympanum, 
including the eustachian tube and mastoid 
process. The latter consists of the 
internal ear or labyrinth, containing the 
auditory nerve endings. In order for 
the function of hearing to be performed 
normally, the sound waves must be trans- 
mitted without interference or obstruction 
to the labyrinth by the conducting ap- 
paratus. 

The perceiving apparatus must receive 
the sound waves and transmit them as 
auditory impulses by the auditory nerve 
to the sensorium, for elaboration and 
interpretation. The manner in which the 
sound waves reach the labyrinth is still a 
mooted question. Dr. A. H. Andrews 
has briefly epitomized the various opin- 
ions held in respect to this, as follows: 

Some believe that the sound waves are 
transmitted from the drum membrane to the 
labyrinth via the ossicular chain and the oval 
window; and that the round window acts as a 
safety valve or pressure regulator for the 
labyrinthine fluid. Others believe that the 
sound waves reach the labyrinth through the 



Defects of Vision and Hearing 83 

round window, and that the function of the 
oval window and the ossicles with their muscles 
is to regulate the tension of the drum mem- 
brane and the labyrinthine fluid. Still others 
believe that sound waves reach the labyrinth 
through both of these routes; while a fourth 
class believes that in addition to these routes 
the outer bony wall of the labyrinth is equally 
responsible for the transmission of the sound 
waves. 

Whatever view we may take, it is plain 
to be seen that any interference with the 
normal functional activity of either the 
conducting or perceiving apparatus will 
result in impaired hearing or deafness. 
Deafness may be defined as a diminution 
or loss of hearing power, and according 
to the degree, it is either partial or com- 
plete. If the hearing is affected by pecul- 
iar sounds and noises in the ear {tinnitus 
aurum) this is usually described as a dis- 
turbance of the auditory power. 

Objective Symptoms of Deafness. — The 
objective symptoms of partial deafness 
are usually evident in the manner and 
actions of the subject; and yet teachers 



84 Defects of Vision and Hearing 

should distinguish between deafness and 
habits of carelessness and indifference 
or of absent-mindedness in their pupils. 
Listlessness, reverie, inattention, etc., may 
simulate the characteristics of partial 
deafness, and a pupil with good hearing 
power be suspected of a slight defect. 

In partial deafness the defect is be- 
trayed by the pupil failing to catch all of 
the words of an ordinary conversational 
tone; he may. turn his head slightly to 
one side, bringing his ear closer, or into a 
better position for gathering the words of 
the speaker. His facial expression, too, 
is an index of his difficulty in hearing all 
that is being said to him. If he has been 
addressed, and is backward or slow in 
responding, the cause can be depicted in 
the tiny blush on the cheek and the nerv- 
ous twinkle of the eyes. 

In complete deafness, of course, there 
is no response to sounds. In disturb- 
ances of the hearing caused by noises in 
the ear, even though the hearing is very 
good, sometimes pupils appear deaf. 
This is because their attention is directed 



Defects of Vision and Hearing 85 

to these subjective symptoms and annoy- 
ances. 

Subjective Symptoms. — The subjective 
symptoms depend largely on the cause. 
Deafness may exist without pain or head 
noises, and again it may be accompanied 
by an aggregation of symptoms more dis- 
tressing than the simple loss of hearing. 

Since we are now considering deafness 
caused by disturbed function — chiefly of 
the conducting apparatus — we may enu- 
merate some of these cases as follows: 

Deafness due to an impaction of the 
cerumen, or ear wax, in the external 
auditory meatus. This usually gives rise 
to symptoms of irritation and uneasiness 
in the ear. The ear drum may be sensi- 
tive and tender in some forms of deafness. 

Acute non-suppurative catarrh of the 
middle ear (ptitus media without suppura- 
tion). This form is attended by deep- 
seated pain, a feeling of fullness, throb- 
bing, etc., in connection with deafness. 

Acute suppurative catarrh of the middle 
ear (otitus media with suppuration). This is 
characterized by pain, swelling, deafness, 



86 Defects of Vision and Hearing 

etc., and, in addition, a purulent discharge 
from the ear. Chronic catarrhal condi- 
tions of the middle ear, either with or with- 
out suppuration, lead to varying degrees 
of deafness. If the ossicles or small bones 
of the ear are involved by the inflamma- 
tory process, the discharge is fetid. 

Inflammation of the eustachian tube. 
This offers an obstruction to the free 
egress and ingress of air to the middle 
ear and produces disturbance of the 
hearing. 

Many other symptoms exist in connec- 
tion with deafness, originating in the con- 
ducting apparatus, but these may serve to 
illustrate some of the feelings and sensa- 
tions experienced by the partially deaf. 

Determination of the Hearing Pow- 
ers. — A simple and convenient test may 
be made with an ordinary watch, provided 
we know its hearing distance. Let the 
subject be seated comfortably and with 
the eyes closed. Take a watch, say with 
a hearing distance of twenty inches, and 
holding it at some distance from the sub- 
ject, gradually approach the ear under 



Defects of Vision and Hearing 87 

examination. As soon as the subject 
gives evidence of hearing the watch tick, 
we carefully note the distance, and by 
comparison we may arrive at a fair 
quantitative test of the hearing power. 

The distance in inches at which the 
subject hears the watch should be taken 
as the numerator, and the hearing dis- 
tance of the watch as the denominator of 
the fraction indicating this power. 

Qualitative tests of the hearing are 
made by the use of tuning forks. Also, 
the location of the seat of trouble, or the 
part of the ear affected and causing the 
deafness, may be determined by the tun- 
ing fork. 

The human voice serves a very good 
purpose in testing cases of deafness. 
Instead of having the subject repeat 
words and sentences pronounced by the 
examiner, it is better to have him repeat 
numbers spoken promiscuously. 



CHAPTER II 

DEAFNESS IN THE STUDENT 

Deafness in Infancy. — Our purpose is 
to consider the effect of deafness in the 
pupil more especially from the time he 
enters school until he finishes the high 
school or the college. However, it may 
not be undesirable to notice the evolution 
or changes of the hearing powers from a 
state of deafness in the first days of in- 
fancy to the almost incredible acuteness 
of hearing in which the ear is sensible to 
sounds produced by vibrations of more 
than forty thousand per second. 

Preyer tells us that "all children imme- 
diately after birth are deaf." This phy- 
siological deafness soon gives away to the 
perception of sound, unless the child has 
a congenital defect of the auditory ap- 
paratus. 

The sense of hearing, like the other 
special senses, is susceptible of education. 
At first only sensations of sound are per- 



Defects of Vision and Hearing 89 

ceived; but later the mental effects are 
produced. As the child grows older it 
learns to distinguish sounds and refer 
them to their cause, etc. The direction 
of sounds and the distance of their 
sources are matters of judgment and ex- 
perience. Binaural audition — that is, 
hearing by means of the two ears — is an 
advantage in estimating the distance of 
the sonorous body. 

Effect of Deafness on the Scholar. — 
A child that is partially deaf must neces- 
sarily accomplish his work with difficulty. 
He cannot hear well the recitations, nor 
the directions and instructions from his 
teacher. Much repetition of questions or 
answers -by the teacher is subversive of 
good discipline, and if a deaf child does 
not understand what is said, especially 
when the teacher is addressing remarks 
in a general way to the pupils, he fre- 
quently lets it pass by altogether. 

In some grades of the public school 
some teachers find a very popular way of 
imparting information to be the relation of 
a story from real life, or the explanation 



go Defects of Vision and Hearing 

of some important mechanism, as the 
dynamo, or the description of the methods 
in the manufacture of some familiar 
article, such as paper, knives, pens, pen- 
cils, etc. A child affected with deafness 
cannot receive the same benefit from this 
instruction as one with normal hearing. 
He is liable to lose words, or sentences or 
parts of sentences, and thus become con- 
fused and lose interest. The recitation is 
of general benefit to the class, as many 
points of interest are developed that may 
not be stated in the text, but this also has its 
disadvantages to the deaf; the misunder- 
standing of a word may change the entire 
thought, and lead to erroneous conclusions. 

Its Effect on the School. — The 
principle of attention is no less important 
in the function of hearing than in the vis- 
ion of pupils. 

A pupil with defective hearing often 
unintentionally diverts the attention of 
the entire school. If he is to understand 
all that is said, he necessarily must ask to 
have some things repeated; if he appeals 
to the teacher, this causes a break in the 



Defects of Vision and Hearing 91 

continuity of thought between the teacher 
and pupils, and if he asks a fellow student 
for help he may cause his benefactor to 
lose some essential feature of the work. 
This is not cited as a criticism on the deaf 
pupil, but simply to show how deafness 
can interfere with the harmony and work- 
ing of the school. 

There is also a condition of partial 
deafness due to disease of the middle 
ear, which is called Chronic Suppurative 
Catarrh, that we may mention in this 
connection — not because of the symptoms 
of deafness particularly, but because of 
its disagreeable features. 

More than two-thirds of all diseases of 
the ear are due to catarrhal inflammation, 
and ninety-five per cent of all diseases of 
the ear characterized by a discharge are 
due to the above-named disease. If the 
chain of ossicles (bones) are affected, the 
ear becomes offensive. Unless the utmost 
precautions are observed in the matter of 
cleanliness, this becomes very obnoxious 
in the schoolroom. Such cases should 
seek medical advice and treatment. 



92 Defects of Vision and Hearing 

Deafness Affects the Student's 
Work. — Not only is the progress of the 
school work interfered with, but the char- 
acter of the work is modified. The read- 
ing is frequently in monotones, the inflec- 
tion and emphasis are faulty, the modu- 
lation is imperfect, and the general ex- 
pression of the voice is characterized by 
harshness and nasal tones. 

This may result from the fact that the 
student cannot distinguish accurately the 
pitch and intensity of sounds. 

The cultivation of the voice constitutes 
no small part of the work devolving on 
the school. If possible, pupils should be 
taught to produce pure vocal tones of 
natural smoothness and clearness. 

The effect of deafness on the voice is 
also shown in the study of music. Music 
is one of the best methods of cultivating 
the hearing powers; the pupil should 
reproduce the tones of the piano in the 
various keys. Ordinarily it is the low- 
pitched sounds that are the most difficult 
to hear and reproduce. For example, a 
pupil who can hear ordinary conversation 



Defects oj Vision and Hearing 93 

very well at a distance of four or five 
feet, may not be able to hear the low 
tones of the instrument so well, nor the 
sound of a bass drum at some distance, 
nor the roaring of the wind. If the 
internal ear is affected, causing the deaf- 
ness, the high-pitched notes are heard 
less distinctly, or not at all. 

Deafness in Special Education. — Cer- 
tain departments of education and some 
special fields of labor are denied the deaf. 

Among the former which offer an 
obstacle to the deaf may be mentioned 
some departments of business education — 
telegraphy, typewriting, shorthand, etc. 
These require acute hearing power. Of 
the latter we may enumerate railroad 
work, the telephone service, certain de- 
partments of government service, the 
army, the navy, etc. 

Nearly all of these require normal hear- 
ing as a qualification for service. 

Chief among the professions with which 
bad hearing interferes are medicine, law, 
music, school-teaching, etc. 

Those affected with deafness should 



94 Defects of Vision and Hearing 

realize that certain occupations will be 
denied them, and while their education 
should be broad and general in its appli- 
cation, judgment and care should be exer- 
cised in selecting a course of study look- 
ing forward to their life work. 



CHAPTER III 



DEAF-MUTISM 



Its Cause. — The loss of hearing power 
in infancy, or the absence of this special 
sense occurring as a congenital defect or 
as the result of disease, is followed by 
mutism. 

Deaf-mutism does not affect the vocal 
organs except indirectly. The reason 
that the child does not learn to talk is 
because it cannot hear the human voice to 
imitate it. Deaf-mutism may occur if the 
child loses its hearing power soon after it 
has learned to talk, and according to 
some authorities it has occurred in chil- 
dren at the ages of seven or nine, upon 
their losing their hearing at this time in 
life. 

Ordinarily, if the hearing is destroyed 
or absent before the fifth year the child 
will not learn to speak. Among the 
causes which are thought to produce 

95 



96 Defects of Vision and Hearing 

deaf-mutism are heredity, consanguineous 
marriages, inherited diseases, and injuries 
and diseases incidental to childhood, such 
as scarlatina and diphtheria. 

If a child cannot hear sounds of vary- 
ing pitch and intenstiy at the fourth 
week — that is, if it does not give some 
evidence of perceiving loud sound, by 
movement or otherwise — the probabilities 
are that it will never hear, and conse- 
quently, that it will be without speech. 

Objective Symptoms. — The objective 
symptoms of deaf-mutism are evident 
when the conditions are sufficiently de- 
veloped and recognized. As a general 
thing parents do not recognize the defect 
early; rarely before the child should 
begin to talk, or about the end of the 
first year, and then frequently it is attrib- 
uted to slow development. Occasionally, 
where deaf-mutism occurs as a congenital 
defect, parents insist that the child has 
been able to hear and that the deafness 
has occurred recently. 

Some of the prominent symptoms that 
may be observed are a blank look in the 



Defects of Vision and Hearing 97 

presence of noise, and a changeless ex- 
pression of the countenance when at- 
tempts are made to attract the child's at- 
tention by loud sounds, such as shrill 
whistles or musical instruments, etc. 

The child's countenance may respond 
to the smiles of the parent and to various 
gesticulations, and these are usually given 
while the anxious parent is talking to the 
unfortunate child, and must be carefully 
attributed to impressions made on its 
vision rather than on its hearing. 

Subjective Symptoms. — The subjective 
symptoms are not so easily determined. 
No doubt the deaf mute realizes by some 
subjective sensation the condition of his 
defective auditory apparatus. If he is 
near a large bell that is being rung, or a 
drum that is being sounded, he can feel 
the vibrations distinctly, and perhaps 
loud sounds produce some effect on the 
nervous system through the medium of 
the ears, even though the sensations can- 
not be translated as sounds. 

Other subjective sensations, such as the 
consciousness of the presence and posi- 



98 Defects of Vision and Hearing 

tion of an external object, and also of its 
absence, are shown in the pressure of the 
atmosphere on the tympanum. 

Professor James illustrates this in the 
following interesting manner: 

The tympanic membrane is, furthermore, 
able to render sensible difference in the pres- 
ence of external atmosphere, too slight to be 
felt either as noise or in this more violent 
way. If the reader will sit with closed eyes 
and let a friend approximate some solid object, 
like a large book, noiselessly to his face, he 
will immediately become aware of the object's 
presence and position — likewise of its depar- 
ture. A friend of the writer, making the ex- 
periment for the first time, discriminated 
unhesitatingly between the three degrees of 
solidity of a board, a lattice frame, and a sieve, 
held close to his ear. 

Now as this sensation is never used by ordi- 
nary persons as a means of perception, we may 
fairly assume that its felt quality, in those 
whose attention is called to it for the first 
time, belongs to it qua sensation, and owes 
nothing to educational suggestions. But this 
felt quality is most distinctly and unmistakably 
one of vague spatial vastness in three dimen- 
sions — quite as much so as is the felt quality of 



Defects of Vision and Hearing 99 

the retinal sensation when we lie on our back 
and fill the entire field of vision with the empty 
blue sky. When an object is brought near the 
ear we immediately feel shut in, contracted: 
when the object is removed, we suddenly 
feel as if a transparency, clearness, openness, 
had been made outside of us. And the feeling 
will, by any one who will take the pains to 
observe it, be acknowledged to involve the 
third dimension in a vague unmeasured state. 
That the sensation in question is one of tac- 
tile rather than of acoustic sensibility would 
seem proved by the fact that a medical friend 
of the writer, both of whose membrance tympaiii 
are quite normal, but one of* whose ears is 
almost totally deaf, feels the presence and 
withdrawal of objects as well at one ear as at 
the other. 

Examination of Deaf Mutes. — The 
examiner should make careful tests in all 
cases of suspected deaf-mutism, to ascer- 
tain if the deafness is complete or partial. 
In all cases of complete deafness we 
attribute it to a lesion in some part of the 
auditory nerve, and speak of it as nerve 
deafness. 

Middle ear disease, however, has pro- 

L.ofC. 



ioo Defects of Vision and Hearing 

duced such marked deafness in very 
young children that they have become 
deaf mutes; but in these cases the hear- 
ing power is not entirely absent. 

The method employed in determining 
complete deafness is by the use of loud 
sounds. In the examination great care 
should be exercised not to jar the child 
by the violent vibrations from the sound- 
ing instrument employed. Usually the 
examiner stands behind the child and 
rings a bell or sounds a shrill whistle 
(Galton's or Delstanche's). 

If the high notes of a Galton whistle do 
not attract the child's attention, it is very 
good evidence that the seat of the trouble 
is in the auditory nerve or some portion 
of it and the deafness is complete. 

Treatment in cases of absolute deafness 
is useless; if a very slight amount of 
hearing power can be detected, treatment 
may be of benefit. 



CHAPTER IV 

EDUCATION OF DEAF MUTES 

The Oral System.— The German, or 
pure oral system, became the national 
system in 1778. The idea is to teach the 
deaf to understand speech and to enable 
them to talk. The instruction is imparted 
by the teacher, by movements of the lips, 
tongue, jaws, and muscles of the throat, 
etc. This method, with some modifica- 
tions, has been used in the United States 
for more than a third of a century. Oral 
methods of instruction are now generally 
preferred to all others; pupils educated 
by the oral method either acquire or re- 
gain speech within certain limits. They 
also become more or less proficient in 
reading the lips of others. 

Lip-reading or speech-reading does not 
necessarily imply that the pupil can talk 
understanding^; often his reading is far 
in advance of his articulation. The lip- 



IOI 



102 Defects of Vision and Hearing 

reader comprehends sentences more easily 
than words, and words more readily than 
simple sounds. The speech acquired by 
those born deaf can be readily understood 
by their teachers and friends, as is at- 
tested in the education of thousands of 
deaf mutes. 

The Sign System. — This is usually 
spoken of as the French System. The 
method has for its object the develop- 
ment of the mental and moral powers 
without the aid of articulate speech. Ex- 
perience has shown that the best facilities 
for the acquirement of an education 
among all classes are in human speech, 
and for this reason the sign method or 
silent method has lost favor among edu- 
cators in deaf-mute schools. 

Under some circumstances the sign 
method is to be preferred to the oral 
method. In children of mental obliquity 
or mental deficiency, the sign system has 
the advantage of being more easily learned 
and more readily applied. 

Pupils educated by the silent method 
go through life without speech; before 



Defects of Vision and Hearing 103 

they can comprehend a thing, the thought 
must be translated into signs. 

The Semi-Deaf. — There is a class of 
children denominated as "hard of hear- 
ing"; they are not totally deaf, and yet 
perhaps are too deaf to attend the public 
schools to advantage. It is necessary, 
under these circumstances, to encourage 
their hearing power, and thus save to 
them the power of speech, if possible. 

Such children can find better advan- 
tages in a private or state school for the 
deaf. 

The use of the graphophone has proved 
of valuable assistance to this class of chil- 
dren, under the guidance and direction of 
competent teachers. Oral instruction 
may not improve the hearing, but it 
quickens their perceptive powers, and 
possibly will enable them to continue 
to communicate with others in their own 
language. 



MAR 1! *904 



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